1. Field of the Invention
The present invention relates to an intake system of an engine in which an air cleaner is connected to the upstream end of an induction system of the engine, and particularly, relates to the improvement of an intake system by reducing the intake noise of an engine in an air cleaner.
2. Description of Background Art
Heretofore, as disclosed in Japanese published patent application Ser. No. 2,516,676, it is known that the intake noise of an intake system of the engine can be reduced by forming an air intake of an air cleaner like a passage.
However, in the above-mentioned conventional type intake system, since the air intake is a passage which slightly disturbs air intake, the conventional type intake system is not suitable for an intake system of an engine for a motorcycle used for racing, in which high engine output is regarded as important, for example.
Thus, until now, when engine output is regarded as important during operation, the air cleaner is replaced with an air cleaner provided with an air intake having a large opening. However, with this conventional configuration, the work to replace the air cleaner is very troublesome.